<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>互联网获取信息来源</title>
</head>
<style>
    .blue span{
        width: 20%;
        height: 5rem;
        background-color: blue;
    }
    .red  span{
        width: 80%;
        height: 5rem;
        background-color: red;
    }
  div{
        width: 100%;
        height: 5rem;
    }
</style>
<body>

<div>
            <span class="blue">
666
            </span>
    <span class="red">
666
            </span>
</div>

</body>
</html>